System for the transmission of angular motion



I 1,637,039 July 1927" E. M. HEWLETT ET A SYSTEM FOR THE TRANSMISSION OF ANOULAR MOTION Filed Dec. 1924 Inventors: Edward M. Hewlett, WcildoWWil lard, gj Their" Attorney.

Patented July 26', 1927. 2

UNITED STATES.

r 1,637,039 PATENT OFFICE.

EDWARD I. AND WALDO W. WILLARD, OI SCHENECTADY, N EW YORK, AS- SIGNOBS TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

8Y8!!! FOR THE TRANSIIBSION OI ANGULAB IOTION.

Application fled December 5, 1924. Serial No. 754,826.

'Our invention relates to systems for the transmission of angular motion and has for its object the provision of means whereby when the transmitting device is inoperative .5 or for. an reasoncannot be used, other devices in t e system may be used as a transmitting device.

More specifically our invention relates to systems for the transmission of angular motion in which transmitting and receiving devices of the alternating current type are used and also an inductive device for introducing corrections.

In carryin out our invention, we provide means where y the inductive 'device for introducing corrections may be utilized in emergencies as a transmitting device.

For a more complete understanding of our invention reference should be had to the accompan ing drawing, the sin 1e figure of which ows in diagrammatic ashion a system for the transmission of angular motion embodying our invention.

Referring to the drawing, we have shown our invention in one form as applied to the driving of a remotely situated indicating device, shown as a dial 10, in response to the angular movements of a telesco e 11, or other object, in a predetermined pane, such 30 as a horizontal plane. Connected to the telescope throu h suitable gearin 12 is a motion transmitting device 13. a his transmit-- ting device is provided with a bi-polar field winding 14 preferably mounted on the rotor, and a polycircuit armature winding 15 on its stator shown as physically simi ar to a three? hase delta connected armature winding. e dial is driven by a receiving device 16, similar in construction the transmitting device 13, havin a single circuit field winding 17 and a po ybircuit armature winding 18. The dial may be secured to the rotor shaft 19 of the receiving device.

Like points of the two armature windings and 18 are electrically connected together and, asshown, a differential device 20 for introducing corrections may be interposed in these connections, such as described and claimed in our Patent No. 1,612,117, 50 dated December 23, 1926. This differential device comprises two inductively associated three-circuit windings 21 and 22,

winding 21 being connected to .the armature winding 15 through conductors 23, '24 and 25 and a switch 26, while winding 22 is connected to winding 18 through conductors 27, 28. and 29. One of the windings of the differential device is rotatably mounted. As shown, the winding 21 may be rotated b means of a shaft 30 on which it is mounte the shaft being turned by a suitable hand.- wheel 31. A dial 32 is provided on the shaft 30 and cooperating with the dial is a stationary pointer 33$whereby corrections can be accurately introduced. The field windings 14 and 17 are connected to a suitable source of alternating current sup 1y 34.

In the operation of transmitting and receiving devices of this character, the field windings induce electromotive forces in the circuits of the armature windings, the relative values and directions of these electromotive forces varying in accordance with the relative angular position of the respective field winding. When the two rotors are in corresponding angular positions, the electromotive forces induced in the armature windings are respectively ual and opposite to each other, and since 1i e points of the two windings are connected, the electromotive forces are also in opposition to each other and consequently no currents are set up. Upon rotation of the field windin of the transmitter, however, a new set 0 electromotive forces is induced in the armature circuits of the transmitter, and as a result the electromotive forces of the two devices become unbalanced and currents are set up.

This results in a torque bein applied to the rotor of, the receiver where y it is turned to a position in which the electromotive forces again balance, this osition corre' sponding to the position of t e transmitter.

When the two windings of the differential device 20 are in corres onding angular positions, as shown, the di erential device has no effect on the set of electromotive forces transmitted to it from the transmitter. B turning winding 21 bymeans of handw eel 31 the differential device is caused to transmit a different set of electromotive forces; i. e., the set of electromotive forces induced in the winding 22 and applied tothe receiving device will be different from the set impressed on winding 21 b the transmitting device.

This change in t e set of the electromotive forces is proportional to the amount of angular dis lacement of winding 21 and any desired changes or corrections may thereby be introduced in the angular position of the dial independently of the transmitting device.

In certain cases upon damage to or failure of the transmittin device, it is very essential to have imme iatel available auxiliary transmitting means which can be used temporarily to at least approximate the operation of the transmitting device, We have provided means whereby the differential de- 1 e the field produced by winding 14, the dif-' ferential device would in fact be a transmitter. We accordingly provide connections whereby the winding 21 can be connected to the supply source 34 in such manner as to produce this field.

The switch 26, interposed in the connections between winding 21 and winding 15, is suitably arranged in 'such manner that the winding 21 may be connected to the supply source 34. For example, the switch may consist ofthree pivoted arms 35, 36 and 37, insulatedfrom each other, each of which moves between a air of stationary contacts By throwing t e arms to the left, as shown in the drawing, the winding 21 is connected to the winding while by throwing the arms to the right into engagement with the other field win from the stationary contacts the winding 21 is connected to the supply source 34. One side of the supply source isconnected through a conductor 38 to the stationary contacts engaged by two of the switch arms,.such as M and 37. The remaining contact engaged by arm 36 is connected through a conuctor 39 to a suitable intermediate-point of an auto-transformer provided with a winding ,40. This rectly across the supp y source 34 and the conductor 39 is connected to it at such a point as to give a suitably reduced voltage or the win .21. This reduced voltage is often by reason of the factthat as ordina y constructed the electroi'notive forces induced in thej circuits of the armature winding of the and .receiving devices and applied to the winding of the difierential device maybe considerably lower than the voltagesapplied to the as p y source 34. The difierent device there ore adapted for the full source 84. a

may not "be 'A sthusconnectedfitwillbeobservedthat =onthewin withtheswitchQBthrowhtotherighQtwo dmg40; Thewin 21isthus caumdto produces b'- dcorrespondingtothefieldprbsis d-bywinding various modifications thereof will su 40-is connected di- .volta'ge of the supply 14. The difierential device can, therefore, be

used in the same manner as the transmitter 13. By turning the winding 21 by means of the handwheel 31 .the movements and positiondof the dial 10 can be controlled as de- Sll'e While we have described our invention as embodied in concrete form and as operating in a specific manner in accordance with the patent statutes, it should be understood that we do not limit our invention thereto, since 6st themselves to those skilled in the art with out departing from the irit of our invention, the scope of which is set forth in the annexed claims.

What we claim as new and desire to secure by Letters Patent of the United States, is;-

1. A system for the transmission of angular motion comprising an inductive transmitting device, an' inductive receiving device,-a source of alternating current supply connected to said devices, connections between said devices including inductive means for introducing corrections, said inductive means .be' provided with relatively adjustable win and means for disconnecting said transmitting device and for connecting said inductive means to said supply source.

2. A system for the tron of lar motion comprisin a transmitting device provided with a sing e circuit field lar motion comp I 1 a transmitting device provided with a circuit field win and 'a pol circuit armature winding, one o said w n being rotatably mounted, a receiving device having win a source of alternating current suppliyccnnected to the field windings of said evices, a correction device having relatively rotatable polycircuit windings, connections between the windings of said correction device and the armature win of said Ill transmittin device and for connecting said of the terminals of w correction evice to said supply-source.

to PP 0m 4. A system'for the on of anguw theothertermmahsco toatap larmotioncomp'" atransmittingdevi provided with asingecircuit field I and a three-circuit one receivin device having similar windings, a

single ase source of supply connected to the fiel% windings of said evices, a correction device having relatively rotatable threecircuit windings, connections between the windings of said correction device and the armature windings of said transmitting and receiving devices respectively, and a switch for disconnecting said transmitting device and for connecting the corresponding winding of said correction device to said supply source so that two of the terminals of said correction device winding are connected together. 7

5. A system for the transmission of angulor motion comprisin a transmitting device provided with a sing e circuit field winding and a three-circuit armature winding, one of said windings being rotatably mounted, a

20 receiving device having similar windings, a

single phase source of supply connected to the field windings of said evices, a correction device having relatively rotatable threecircuitv windings, connections between the windings of said correction device and the armature windings of said transmittin and receiving devices respectively, a switc for disconnecting said transmitting device and for connecting the corresponding winding of said correction device to said suppl source so that two of the'terminals of sai correction device winding are connected together, and means for reducing the voltage impressed on said correction device winding rom said supply source.

In witness whereof, we have hereunto set our hands this fourth day of December, 1924.

EDWARD M. HEWLETT. WALDO W. WILLARD. 

